Infrared radiant heater tubes are frequently employed in warehouses, factories, and similar commercial settings to provide a suitably warm working environment during cold weather. Such heater tubes are typically suspended from the ceiling or other overhead structure, and radiate heat downwardly to the working areas to be warmed. An example of an infrared radiant heater system is shown in U.S. Pat. No. 4,319,125, issued Mar. 9, 1982, to Prince.
As shown in the Prince patent, an infrared radiant heater system includes a plurality of individual tubes, with each pair of adjacent tubes being interconnected by a clamp which also serves to secure the assembly to a suspension device such as a turnbuckle. The heating tubes disclosed in the Prince patent have straight ends, thereby necessitating the use of some type of coupling device (clamp 20) to connect the end of each tube to the end of the next adjacent tube. It is also known in the art to utilize tubes having a straight end and an expanded end, so that the straight end of one tube may be telescopically inserted into the expanded end of the next tube to form what is commonly referred to as a "slip joint."
The use of slip joint type radiant heater tubes has met with considerable acceptance in the industry. One drawback to the use of such tubes, however, has presented a problem. In order to create an acceptably tight slip joint, brackets are commonly attached to both ends of a pipe section by welding, screwing, riveting, or other conventional fastening means. The bracket secured to the expanded end of one pipe is then bolted to the bracket attached to the straight end of the next adjacent pipe to yield an acceptable slip joint, with one such bracket at each joint being securable to the suspension apparatus. This system of connecting and suspending heater tubes is costly due to the number of components involved and the labor required to secure brackets to each end of the tubes. Additionally, since welding is a common method of attaching brackets to the tubes, distortion of the tube ends presents a particular problem with close tolerance slip joints. Accordingly, a need has arisen for an improved suspension and connection apparatus specially adapted for slip joint type heater tubes.
With conventional suspension and connection systems, it is frequently necessary to simultaneously support both heater tubes in an adjoining pair while securing the connection between the tubes and the suspension mechanism. If either tube is insufficiently supported during the assembly process, the unsupported tube may fall, thereby creating an extremely dangerous situation for assembly personnel. It is desirable to have an integrated suspension and hanging system which provides acceptable support for each individual heater tube while successive tubes are being interconnected.